Machine for making stabilized capsules



March 2l, 19,61 J. B. vAuGHAN l MACHINE FOR MAKING STABILIZED CAPSULES original Filed oci. 2s, 1957 2 Sheets-Sheet 1 lid Uuu DHB 1.a Q M l| i RH m l l mG *mi NU wm w I ,s m T .M UNL, H m mw P Q Mmm A E.. n, M4 J W Q\ W- n, w N

MarchfZl, 1961 J.. B. vAuGHAN 2,975,752

MACHINE FOR MAKING STABILIZED CAPSULES Original Filed Oct. 23, 1957 2 Sheets-Sheet 2 IIIIIIH NVENToR. JOSEPH B. VAUGHAN www ATTORNEYS Umd States PainfO 2,975,752 l MACHINE Fon MAKiNG sTABrLlzED CAPSULES Joseph B. Vaughan, Norwood, Ohio, assignor to Lloyd Brothers, Inc., Cincinnati, Ohio, arcorporation of Ohio Original application Oct. 23, 1957, Ser. No. 691,976. 'll)i;ided and-this application June 2, 1958, Ser. No. 3 ,314

s claims. (ciglia-13) Vments' orally. is to enclose the substance in a shell of gelatin inthe form of what are known as soft gelatin capsules. '[fhese. capsules vary in stability toward heat and humidity, and when certain medicaments are en-l closed, the capsules tendytoi .deteriorate and permit the i contents of the capsulesf'to'leak. property ofcertain soft gelatin capsules results inarelatively unsatis-Y faQtQIY form lof.*medication for Vthe's'ubstance involved Patented Mar. 21, 1961 2. are removed and the residual formaldehyde .vapors remaining on the capsules are permitted to evaporate by exposureto air. Y

` While the capsules are exposed to the formaldehyde gas, the trays of `capsules are agitated or stirred inorder e to insure reaction at all surfaces of the capsules. The

sincefcapsule vdeteiorzttion, often results in both lossto Y Vthe manufacturer and to the consumer whorhas pur-- chased the item.

. It is known `that gelatin used in preparing theso'ft gel-atincapsuleshell will undergo a chemical reaction with formaldehyde, AThe compound 'so provided isin-` l soluble in water :and onlyA slowly4 soluble `in dilute acid or alkali. In thepas. gelatin coated `capsules have been treated by dipping inan aqueous .solution of formalde` hyde to renderv them enteric coated, i.e., 'to provide a ,e

coating which'willresistthe action of stomach fluids but Y permiteventual solution in the alkaline iluids ofthe intestinal tract. However, such methods oftreating capsules havefnotbeen satisfactory, because,` when suchfa gelatin coated` tablet has beendipped in an ,-aqueouswsolution of formaldehyde, thereactitnrisa` progressiveone and continues for a protracted period after the Vdipping and drying is completed, 'so that the propertieslof the nal productcannotberegulated; *i f. $7

I` have found that, whenjtsoft'fgelatin'capsules are treated "with Yor exposed-to an atmosphereofffformaldeh yde gas,;a ,P1;oduct;can be ,formed which is s tablenand does vnot continue te change progressively.' '.The Vcapsules are? rerideredtlesisv subject to deterioration ycaused. by

in s com l "taysi'n 'ajclc'ised` chamber in. whichhumid! e car ully 'regulated'throughjudicious choice ,of

ity is formaldehyde@ grate Manci" abs t the'. alkaline rintestinall;region.Y r" l dltlijselaiiiispsles. arejiratsigto an atmospherecontining `flc'rrmaldehydve gas at avcareflillly contolledor predeteriinelrelative humidity for aholds the door in closed position. J

than .message in watertoren; Aaa #2m-..-

'o ,Par-,t thereof, ibeing shown trays have screened bottoms on which the capsules are supported so that the vaporscan readily reach all portions ofthe surfaces ofthecapsules. "Theabove and other objects and features of this invention Will be apparent to those skilled in the -art to which this invention pertains from the following detailed description and the drawings, in which:

Figure 1 is a view partly in side elevation and partly in lengthwise section of a machine for treating capsules constructed in accordance with an embodiment of this invention; l Fig. 2 is a view in section, taken on the line 2 2 in Fig. 1;

` Fig. 3 yis a view in section, taken on the line 3--3 in.

Fig. 1; t

Fig. v4 isLa perspective view of one of a plurality of capsule-holding trays which for-mt` a part of the device, the view beingV directed toward the lower side of the tray; Fig. 5 is an `enlarged view showing details of construction of a capsule-agitating mechanism which forms a partof the machine, various positions lof a, cam which forms and 'double-dot-dash lines; and

,fige 6 isa view insection taken onthe, line 6,-6 inV e ig. 5, an 'agitator-shaft yand members mounted thereon beingftuther broken away. U t

f VInthe following ydetailed description and the drawings, like reference charactersindicate like parts.

`In Figs. l-3 is shown a machine which has an elon- 1 gated main portion or tunnel 10 having side walls 12 yand 13, va bottom. 14, and atop wall 15 (see Fig.

3).V Thewalls of the tunnel 10 are formed of alumif num orstainless steel, or other metal which is unaffected by formaldehydeand Awater vapor. The tunnel is supported on vappropriate legs 1.6. Angle-shaped tracks 17 and `lware attached to side walls 12 and 13, respectively, in any suitable manner (not shown) and extend the lengthof the tunnel. Thetracks support a plurality of trays 1 9, whichcan Abe .slid along the tunnel. As shown in Fig. 4, each 4of the trays 19 includes a box-like rect-angularframework consisting of side frames 21 and end frames 22 whichsupport a screen section 23. The screen section 23-forms the bottom of the tray. As shown in Fig.J capsules f2 4-aresupported on the screen.4 Each l ofthe ,capsules is of usual form and includesra hollow shelljZAS'ofgelatin insidewhich is amedicament 25a.

The screen is attached to the side..and end frames 21 and 22 byfmolding members 26 and 27 (Fig. 4), respectively, which hold the screen, section in place. Rigid brace members 2,8 andt29 span the moldings 21 andy 22,

respeotivelyfas shown most clearly in Fig. 4` and cross attire center of the gbotto'm of the tray, spaced below the screenasshownin Fig;;5;

t VIenedeterrnineil aridfd'efinite period of timev To accom-` h entiondhin layers Vsoft .gelatin capsules Asshown `in Fig. 1., the trays canbeinserted atone endfof the tunnel through a door 31, and each tr-ay is moved -alongthe tunnel when another tray is inserted through the door 31. `The door 311 is mounted on hinges 30, and can swing to the left to; open position. An appropriate catch (not shown) VThe tunnel is divided into an inlet or `entry section 32, a main section 33,.and an, 31,41as Shown.in-Fis.y 1.-V

The: inlet sectionV 32 separated from the main, section 33 by anV upper wall section 36 u w e I e e e E i n J 1`=`tandalower wa113section7. ,The lower Wall section 37 sureA for th'prdeternn t v"ned period of time, the capsules extends upwardly from the bottom wall ofthe tunnel to in full lines, dotted lines as'shownin Figs. 1. and 2 outlet ordischarge section. Y'

tunnel wherecapsules inf the loaded tray are exposed to- Y When the loaded tray reaches approximately the center of the tunnel, theloaded tray is raised and dropped by an a'gitating mechanism 61. Details of the agitating mech-g anism 61 are shown in Figs. 5 and 6. -A tubular guide 62v extends through thebottom wall 14 of the tunnel and substantially the bottoms of trays on the tracks 17 and 18. The upper wall section 36 carries a flap 38 of rubber, or the like, which hangs downwardly therefrom. As shown in Fig. 1, theplowerl edgeof thetlap 38 engages ,the upper edge of one of the end frames 2.2 of one of the trays when the trays are at rest inside the tunnel in the position shown in Fig. l to form a substantially tight air lock between the inlet section and the main section. Similarly, an air lock is formed between the main section and the outlet section by a lower wall section 41 and an upper wall section 4Z. The upper wall section 42 carries a rubber ap 43, as shown most clearly in Fig. 3. An additional air lock is provided in the outlet section by lower and upper -wall sections indicated at 44 and 46, respectively, and a ap 47. When a tray has traveled the length of the tunnel, the tray can be removed therefrom through a door 49 which can swing to the right as shown in Figs. l and 2 on hinges 51. An appropriate catch (not shown) holds the door 49 in closed position.

Chemical containers 52, 53, and 54 are mounted in the tunnel below the tracks 17 and v18. The container 52 is in the inlet section, and the containers 53 and S4 are in the main section of the tunnel. The container 52 is loaded with calcium chloride `which acts as a desiccant removing moisture from the air entering with the capsules into the inlet sectionso that moisture is eliminated from the air surrounding the capsules before the capsules enter the main section of the tunnel and in order to eliminate effects caused by variations in the humidity of the ambient air.

The containers 53 and 54 are located inside the main section o-f thel tunnel. The containers 53 contain an aqueous solution of formaldehyde. The containers 54 contain a concentrated aqueous solution of selected salts for maintaining a predetermined relative humidity'inside the main section of the tunnel. In the preferred operation of the tunnel, the containers 53 contain commercial formaldehyde solution which is approximately at 37% aqueous solution Vof formaldehyde, and the containers 54 contain a mixture of sodium nitrate, sodium chloride, and potassium nitrate, together with a concentrated aqueous solution of these salts. The salt` solution controls the humidity in the main section of the tunnel so that the relative humidity therein is approximately 30%.

The solutions in the containers 513 and 54 may be replenishedfwhen necessary, by means of'iiller containers S6 and 57. The ller container 56 is connected to the formaldehyde containersV 53 by a line 58 and the` filler container 57 is connected to the salt solutioncontainers` 54 by a line 59 as shown in Fig. -2. VWhen'the supply of salt solution in the salt solution container is depleted, water may be added to the filler container 57 to-{ow through the line 59 to the salt solutioncontainers 54. When the supply of formaldehyde solution in theV containers 53 is depleted, additionalformaldehyde solution is added to the filler container 56 -to ow through the line S to the formaldehyde containers 53.

When the tunnel is to he used, empty trays are inserted into the tunnel until there is acomplete set of empty trays extending the length thereof.` Thena tray is loaded with capsules. For best results, there -are no more than two or three layers of'capsules in the tray resting on the screening thereof. Thev inlet door 31 is opened andthe loaded'tray is advanced into the inlet chamber, where the tray remains with the door closed for sufcientV time to dry the air Vsurrounding the capsules. Then, as additional trays are inserte'dinto the tunnel, the loaded tray is advaneed'therealong into the main section of the vapors of formaldehyde having a controlled humidity.

4 is attached thereto by an appropriate bracket 63. A shaft 64 moves up and down inside the guide 62. A plate 66 at the upper end of the shaft 64 is engageable with the middle portion of the lengthwise brace 29 of the tray thereabove when the ytrays are stationary in the position shown in Figs. 1 and 2. The shaft is raised by operation of a cam 67. The cam 67 is mounted on a cam shaft 68 which is driven byan electricmotor 69. The caml engages a ring bearing 70 which is rotatably mounted on a pin or stud 71. The stud 71in turn is mounted inthe agitator shaft 64 and reciprocates in a slot 72 in the guide 62.

Y Asthe cam shaft and cam swing from thev position shown in dashed lines to the position shown in fulllines, the cam raises the shaft 64 to raise the tray thereabove. Then, when the cam swings farther in a countenclockwise direction, the cam comes out from beneath the ring bearing and the agitator shaft 64 andthe tray thereabove is dropped suddenly to cause agitation of the capsules in the tray.

The electric motor may be connected to an appropriate source of power through appropriate switches (not shown). When a loaded tray has been pushed to the position above the guide, the motor may be energized for a suiiicient time to cause the tray to be raised and dropped one or more times. Then, lwhen the cam has reached the position shown in double-dot-dash lines, the motor may be stopped until another tray is inserted to ad- Vance each tray in the tunnel one tray length.

In the operation of the tunnel, at predetermined time intervals trays filled with capsules are loaded into the tunnel. As each tray is inserted, another tray is removed from the outlet lend. The timing or'V interval of time betweenintroduction of trays, varies with the capsules treated. For an average type of capsule, the time of exposure in the main section of the-tunnel is about one hour. However, since the consistency of the gelatin of capsules varies, the required time may vary and is determined by testing a small sample of capsules -from a lbatch to determine the length of exposure necessary to r'esult in the desired hardening and enteric coating. The capsules of the batch are tested by reaction with artificial gastric juices and articial intestinal fluid. In testing a batch, a sample of capsules is exposed to the fumes in the main section of the tunnel for one hour. Then, after removal lfrom the tunnel, portions of the sample are allowed to stand for periods of one, two, four, six, eight and ten days. Results of testing one sample batch are shownl in the following table:

Artificial gastric juice:

1st day disintegrate in 2O minutes. 2nd day disintegrate in '45 min- 11 9S. tl day no disintegration in 1` 6th day no disintegration in hr Disintegrates in 2% hrs. 8th day no disintegration in 1 r Disintegrates in 2% hrs. 10th day no disintegration in 1 hr Disintegrates in 2% hrs. The tabulated results indicate that after six days, the reaction had terminated and a. stable coating had been achieved. If, in another sample batch,ts'ubstantially more than 21/2 hrs. is required to cause disintegration in articial intestinal fluid, an additional sample batchis pre- Arttacial intestinal' sind Disntegrates in 2 hrs.

pared using a shorter period of exposure to fumes in the main section of the tunnel. Where, on the other hand, in a sample batch, there Vis disintegration in artificial gastrie juices within less than 1 hour, even after six or more days, an additional batch is given a longer period of exposure in the main section of the tunnel before testing.

In the usual batches of capsules the time required in y. the main section of the tunnel to produce a stable enteric coating, varies from 15 minutes to Z'hours.

The humidity inside, vthe tunnel may be varied by using other salt solutions forcontrolling'the humidity.

If much greater humidity is employed, however, the reaction process is at a faster rate and can not readily be controlled. If, on the other hand, a lower humidity is employed, the reaction is substantially slower.

The treated capsules are strongly resistant to deterioration or leaking even at elevated temperatures which cause leaking of ordinary or untreated capsules.

The method and device for hardening and enteric coating capsules described above and illustrated in the drawings, are subject to modification without departing from the spirit and scope of the appended claims.

Having described my invention, what I claim as new and desire to secure by Letters Patent is:

1. A machine for hardening the surface of gelatin capsules which comprises an elongated, enclosed tunnel having an inlet section, a main section, and an outlet section, means for supporting a plurality of trays in said tunnel for advancing therethrough, means for substantially sealing the inlet and outlet sections from the main section, a desiccant in the inlet section for drying the air therein, open-topped containers inthe main section, formaldehyde solution in at least one of said containers, a humidity controlling solution in at least another of said containers, whereby an atmosphere of predetermined humidity and concentration of formaldehyde is maintained in the main section of the tunnel for forming a coating on gelatin capsules held in said trays as the trays are moved through the tunnel, and means for agitating the trays when inthe main section to stir capsules in the trays.

2. A machine @for hardening the surface of gelatin capsules which comprises an elongated, enclosed tunnel having an inlet section, a main section, and an outlet section, tracks extending along opposite sides thereof for supporting-a plurality of trays in said tunnel for advancing therethrough, each of said trays having a screen bottom, means for substantially sealing lthe inlet and outlet sections from the main section, a desiccant in the inlet section for drying the air therein, open-topped containers in the main section below the tracks, formaldehyde solution in at least one of said containers, a humidity controlling solution in at least another of said containers, whereby an atmosphere of predetermined humidity and concentration of formaldehyde is maintained in the main section of the tunnel for forming a coating on gelatin capsules held in said trays as the trays are moved through the tunnel, a shaft reciprocably mounted for up and down motion through the bottom of the main section of the tunnel between the tracks, and engageable with one of the trays on the tracks, and means engageable with the shaft to raise the shaft #and said one of the trays to cause said one of the trays to drop to the tracks to stir the capy sules which comprises an elongated, enclosed tunnel having an inlet section, a main section, and an outlet section, means for supporting a plurality of trays in said tunnel for advancing therethrough, means for substantially sealing the inlet and outlet sections from the main section, open-topped containers in the tunnel, formaldehyde solution in at least one of said containers, a humidity controlling solution in at least another of said containers, whereby an atmosphere of predetermined humidity and concentration of .formaldehyde is maintained in the main section of the tunnel for forming a coating on gelatin capsules held in said trays as the trays are moved through the tunnel, and means for agitating the trays when in the tunnel to stir capsules in the trays.

4. A machine for hardening the surface of gelatin capsules which comprises an elongated, enclosed tunnel, means for supporting a plurality of trays in said tunnel for advancing therethrough, means for substantially sealing ends of the tunnel, open-topped containers in the tunnel, formaldehyde solution in at least 'one of said containers, a humidity controlling solution in at least another of said containers, whereby an atmosphere of predetermined humidity and concentration 'of formaldehyde is maintained in the tunnel rior forming a coating on gelatin capsules held in said trays as the trays are moved through the tunnel, and means for agitating the trays when in the tunnel to stir capsules in the trays.

5. A machine for hardening the surface of gelatin capsules which comprises an elongated, enclosed tunnel, means for supporting a plurality of trays in said tunnel for advancing therethrough, means for substantially sealing ends of the tunnel, an open-topped container in the tunnel, formaldehyde solution in said container, whereby an atmosphere of predetermined concentration of formaldehyde is maintained in the tunnel for forming a coating on gelatin capsules held in said trays as the trays are moved through the tunnel, and means for agitating the trays when in the tunnel to stir capsules when in the trays.

References Cited in the file of this patent UNITED STATES PATENTS 1,230,068 Elliott June 12, 1917 1,710,747 Smith Apr. 30, 1929 1,744,884 Greiner Jan. 28, 1930 1,916,455 Wright July 4, 1933 1,938,581 Cope et al Dec. 12, 1933 2,511,666 Barr June 13, 1950 2,519,250 Jeppson et al Aug. 15, 1950 FOREIGN PATENTS 514,047 Great Britain Oct. 30, 1939 470,045 Canada Dec. 12, 1950 

